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Welles started by stripping his 911 to a bare tub. With the exception of some surface rust in the interior, the tub was nearly rust-free. “The main thing I did welding-wise was to repair a ton of holes from an aftermarket air-conditioning system that I removed,” he says.

He sent the chassis to Kevin Mentzer of Automotive Innovations in Van Nuys for paint, one of the few areas Welles couldn’t tackle on his own. He chose to retain the car’s original color, Signal Orange. While the Porsche was getting painted, Welles went to work on the engine.

“I was originally going to build my 2.2 out to a 2.4, but I came across a used 2.7 so cheap I couldn’t pass it up,” says Welles. Even better, the 2.7 had the desirable 7R crankcase and was thus a prime candidate as the basis for a hotter street engine. Walt Watson at Competition Engineering was entrusted with resurfacing and machining all components. Welles chose to use Supertec studs, and to have Helicoils and case savers installed as necessary. The case was also modified for a later-style oil bypass.

When the case returned, Welles added a later oil pump, then bolted the freshly micropolished crankshaft to factory connecting rods. New Mahle 2.7 RS-spec pistons with an 8.5:1 compression ratio came next, with an anti-friction coating on their skirts and an anti-heat coating on their domes. Welles took an alternate route when it came to the camshaft grind, foregoing high-revving RS-spec camshafts for more street-friendly 911E cams.

The six individual cylinder heads were fly cut and ported to RS specs for better airflow. Heavy duty, Teflon-coated valve springs actuate valves coated in the same manner as the pistons, with an anti-friction coating on the stems and an anti-heat coating on the faces of the valves.

Fuel delivery is handled by a pair of 40-mm PMO carburetors, a PMO fuel-pressure regulator, and a Pierburg fuel pump. The car’s original gas tank was thoroughly cleaned and then coated with POR-15 to ensure a reliable fuel supply. On the exhaust end, a set of Jet Hot-coated SSI heat exchangers lead into a Dansk muffler. Spark comes via an MSD 6AL-2 ignition system, an MSD Blaster coil, a distributor recurved from CIS specifications to work with carbs, and Clewett Engineering plug wires. An upgraded 95-amp alternator is hidden behind the engine’s cooling fan.

Welles decided to retain the original 901 five-speed transmission, as it had been gone through recently. He cleaned it up and had its magnesium surfaces coated with anti-corrosion coating before bolting it to the engine. Welles replaced all of the bushings in the shift linkage, then ditched the stock shift lever and its associated parts for a Rennshifter short-shift setup.

When the painted body returned, it was time to start bolting parts back onto it. Welles started with suspension, which he had spent considerable time researching. “I wanted something that would handle incredibly well but still be comfortable enough to not make unwitting passengers complain,” he explains. In the end, he chose to use 21-mm Elephant Racing torsion bars with Bilstein HD dampers up front and 27-mm Elephant Racing torsion bars with Bilstein Sports in the rear.

Welles installed a pair of adjustable rear spring plates from a 911 SC. After welding in new anti-roll bar mounts at the rear and then heavily reinforcing them, he installed a 27-mm hollow, adjustable anti-roll bar from Tarett Engineering. Tarett’s 21-mm hollow anti-roll bar keeps body roll in check up front. All of the primary suspension bushings were replaced with Elephant Racing’s poly-bronze bushings, and the steering rack was rebuilt and now actuates 911 Turbo tie-rods. The suspension rebuild was thorough, with every original metal component replated and new bushings installed throughout.

Also from Issue 192

  • Interview: Matthias Müller
  • 2012 Cayman R
  • Huschke von Hanstein
  • 1998 911 Carrera S Cabriolet
  • 1962 356B cabriolet
  • 1979 914-6
  • 1987 944
  • Buyers Guide: 356 and 912
  • 2011 Cayenne
  • Tech Forum
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